Power Reserve Control for Gas Turbines in Combined Cycle Applications

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Eric A. Müller ◽  
Andrew Wihler
Keyword(s):  
Power Plant ◽  
Electricity Market ◽  
Power Output ◽  
Gas Turbines ◽  
Optimal Operation ◽  
Combined Cycle ◽  
Maximum Power ◽  
Frequency Regulation ◽  
Combined Cycle Power Plant ◽  
Maximum Power Output

In order to be able to optimally operate a combined cycle power plant in a liberalized electricity market, knowledge of the plant’s maximum exportable power generation capacity is vital. However, the maximum power output of a power plant is affected by numerous variable factors, such as the ambient conditions at the plant site. In addition, the allowable plant operating range might be narrowed by a compulsory reserve margin, if the power plant is participating in a frequency regulation program. In this paper, a power reserve controller is derived, which facilitates the optimal operation of a combined cycle gas turbine power plant subject to a reserve margin requirement. The power reserve controller is based on a mathematical description of the power plant and uses an adaptation mechanism to predict on a real-time basis the maximum allowable plant load limit. Based on tests on a single shaft combined cycle power plant, the operation of the power reserve controller is demonstrated and its performance is assessed. The test results prove that the controller predicts the maximum power output of the plant with high accuracy and that it is able to maintain a desired reserve capacity for frequency response as specified.

Power Reserve Control for Gas Turbines in Combined Cycle Applications

2011 ◽  
Author(s):  
Eric A. Mu¨ller ◽  
Andrew Wihler
Keyword(s):  
Power Plant ◽  
Electricity Market ◽  
Power Output ◽  
Gas Turbines ◽  
Optimal Operation ◽  
Combined Cycle ◽  
Maximum Power ◽  
Frequency Regulation ◽  
Combined Cycle Power Plant ◽  
Maximum Power Output

In order to be able to optimally operate a combined cycle power plant in a liberalized electricity market, knowledge of the plant’s maximum exportable power generation capacity is vital. However, the maximum power output of a power plant is affected by numerous variable factors, such as the ambient conditions at the plant site. In addition, the allowable plant operating range might be narrowed by a compulsory reserve margin, if the power plant is participating in a frequency regulation program. In this paper, a power reserve controller is derived, which facilitates the optimal operation of a combined cycle gas turbine power plant subject to a reserve margin requirement. The power reserve controller bases on a mathematical description of the power plant and uses an adaptation mechanism to predict on a real-time basis the maximum allowable plant load limit. Based on tests on a single shaft combined cycle power plant, the operation of the power reserve controller is demonstrated and its performance is assessed. The test results prove that the controller predicts the maximum power output of the plant with high accuracy and that it is able to maintain a desired reserve capacity for frequency response as specified.

HRSG Duct Firing Revisited

2018 ◽  
Author(s):  
S. Can Gülen
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Fossil Fuel ◽  
Heat Rate ◽  
Combined Cycle ◽  
Efficiency Improvement ◽  
Combined Cycle Power Plant

Duct firing in the heat recovery steam generator (HRSG) of a gas turbine combined cycle power plant is a commonly used method to increase output on hot summer days when gas turbine airflow and power output lapse significantly. The aim is to generate maximum possible power output when it is most needed (and, thus, more profitable) at the expense of power plant heat rate. In this paper, using fundamental thermodynamic arguments and detailed heat and mass balance simulations, it will be shown that, under certain boundary conditions, duct firing in the HRSG can be a facilitator of efficiency improvement as well. When combined with highly-efficient aeroderivative gas turbines with high cycle pressure ratios and concomitantly low exhaust temperatures, duct firing can be utilized for small but efficient combined cycle power plant designs as well as more efficient hot-day power augmentation. This opens the door to efficient and agile fossil fuel-fired power generation opportunities to support variable renewable generation.

Second Law Efficiency of the Rankine Bottoming Cycle of a Combined Cycle Power Plant

2008 ◽  
Author(s):  
S. Can Gulen ◽  
Raub W. Smith
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Second Law ◽  
Modeling Tools ◽  
Combined Cycle Power Plant

A significant portion of the new electrical generating capacity installed in the past decade has employed heavy-duty gas turbines operating in a combined cycle configuration with a steam turbine bottoming cycle. In these power plants approximately one third of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to develop the combined cycle power plant as a system. Doing so requires a solid understanding of the efficiency entitlement of both, topping and bottoming, cycles separately and as a whole. This paper describes a simple but accurate method to estimate the Rankine bottoming cycle power output directly from the gas turbine exhaust exergy utilizing the second law of thermodynamics. The classical first law approach, i.e. the heat and mass balance method, requires lengthy calculations and complex computer-based modeling tools to evaluate Rankine bottoming cycle performance. In this paper, a rigorous application of the fundamental thermodynamic principles embodied by the second law to the major cycle components clearly demonstrates that the Rankine cycle performance can be accurately represented by several key parameters. The power of the second law approach lies in its ability to highlight the theoretical entitlement and state-of-the-art design performances simultaneously via simple, fundamental relationships. By considering economically and technologically feasible upper limits for the key parameters, the maximum achievable bottoming cycle power output is readily calculable for any given gas turbine from its exhaust exergy.

Second Law Efficiency of the Rankine Bottoming Cycle of a Combined Cycle Power Plant

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
S. Can Gülen ◽  
Raub W. Smith
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Second Law ◽  
Modeling Tools ◽  
Combined Cycle Power Plant

A significant portion of the new electrical generating capacity installed in the past decade has employed heavy-duty gas turbines operating in a combined cycle configuration with a steam turbine bottoming cycle. In these power plants approximately one-third of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to develop the combined cycle power plant as a system. Doing so requires a solid understanding of the efficiency entitlement of both, topping and bottoming, cycles separately and as a whole. This paper describes a simple but accurate method to estimate the Rankine bottoming cycle power output directly from the gas turbine exhaust exergy, utilizing the second law of thermodynamics. The classical first law approach, i.e., the heat and mass balance method, requires lengthy calculations and complex computer-based modeling tools to evaluate Rankine bottoming cycle performance. In this paper, a rigorous application of the fundamental thermodynamic principles embodied by the second law to the major cycle components clearly demonstrates that the Rankine cycle performance can be accurately represented by several key parameters. The power of the second law approach lies in its ability to highlight the theoretical entitlement and state-of-the-art design performances simultaneously via simple fundamental relationships. By considering economically and technologically feasible upper limits for the key parameters, the maximum achievable bottoming cycle power output is readily calculable for any given gas turbine from its exhaust exergy.

Evaluation of Different Alternatives of Power Augmentation for an Existing Combined Cycle Power Plant in Brazil

2007 ◽  
Author(s):  
Ce´sar Celis ◽  
Vinicius P. de Avellar ◽  
Sandro B. Ferreira ◽  
Sergio L. Braga
Keyword(s):  
Power Plant ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Financial Analysis ◽  
Combined Cycle ◽  
Internal Rate Of Return ◽  
Combined Cycle Power Plant ◽  
Augmentation Techniques ◽  
Plant Power

Not only in simple cycle power plants, but also in combined cycle power plants based on gas turbines, the power output is considerably reduced with the increase of the ambient temperature. Many technologies for power augmentation of gas turbines have been proposed along the last decades, and several systems have already been applied in real plants. Power augmentation techniques are concentrated on the philosophy of increasing the mass flow rate going through the gas turbine. The goal of this paper is to review the state-of-the-art of the different technologies of power augmentation available today for gas turbines, as well as to evaluate and to select the best alternative of power augmentation for an existing combined cycle power plant in Brazil. The calculations are carried out using an in-house computer program, called the Power Augmentation Technologies (PAT) model, developed for thermal performance modeling and financial analysis. In order to validate the computational model developed, the authors carried out comparisons between the results obtained with this model and data obtained from literature. For the specific combined cycle power plant analyzed in this work, and considering the internal rate of return and the pay-back period as the main investment economic indicators determining the implementation of a project developed for increasing the plant power output, the results show that the power augmentation systems based on evaporative coolers are the most suitable for this plant.

Performance Analysis of a Combined Cycle Power Plant Through Exergetic and Environmental Indices

2017 ◽  
Author(s):  
Edgar Vicente Torres González ◽  
Raúl Lugo Leyte ◽  
Martín Salazar Pereyra ◽  
Helen Denise Lugo Méndez ◽  
Miguel Toledo Velázquez ◽  
...  
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Environmental Indices ◽  
Combined Cycle Power Plant ◽  
Combustion Gases ◽  
Combined Cycle Plant ◽  
Exergetic Analysis ◽  
Gas Turbine Power Plant

In this paper is carried out a comparison between a gas turbine power plant and a combined cycle power plant through exergetic and environmental indices in order to determine performance and sustainability aspects of a gas turbine and combined cycle plant. First of all, an exergetic analysis of the gas turbine and the combined is carried out then the exergetic and environmental indices are calculated for the gas turbine (case A) and the combined cycle (case B). The exergetic indices are exergetic efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy ratio, environmental effect factor and exergetic sustainability. Besides, the environmental indices are global warming, smog formation and acid rain indices. In the case A, the two gas turbines generate 278.4 MW; whereas 415.19 MW of electricity power is generated by the combined cycle (case B). The results show that exergetic sustainability index for cases A and B are 0.02888 and 0.1058 respectively. The steam turbine cycle improves the overall efficiency, as well as, the reviewed exergetic indexes. Besides, the environmental indices of the gas turbines (case A) are lower than the combined cycle environmental indices (case B), since the combustion gases are only generated in the combustion chamber.

Combined Cycle Off-Design Performance Estimation: A Second-Law Perspective

2011 ◽  
Author(s):  
S. Can Gu¨len ◽  
Joseph John
Keyword(s):  
Power Plant ◽  
Electricity Market ◽  
Combined Cycle ◽  
Performance Estimation ◽  
Second Law ◽  
Combined Cycle Power Plant ◽  
Design Performance ◽  
Cycle System ◽  
Wide Range ◽  
Exact Design

A combined cycle power plant (or any power plant, for that matter) does very rarely — if ever — run at the exact design point ambient and loading conditions. Depending on the demand for electricity, market conditions and other considerations of interest to the owner of the plant and the existing ambient conditions, a CC plant will run under boundary conditions that are significantly different from those for which individual components are designed. Accurate calculation of the “off-design” performance of the overall combined cycle system and its key subsystems requires highly detailed and complicated computer models. Such models are crucial to high-fidelity simulation of myriad off-design performance scenarios for control system development to ensure safe and reliable operability in the field. A viable option in lieu of sophisticated system simulation is making use of the normalized curves that are generated from rigorous model runs and applying the factors read from such curves to a known design performance to calculate the “off-design” performance. This is the common method adopted in the fulfillment of commercial transactions. These curves, however, are highly system-specific and their broad applicability to a wide variety of configurations is limited. Utilizing the key principles of the second law of thermodynamics, this paper describes a simple, physics-based calculation method to estimate the off-design performance of a combined cycle power plant. The method is shown to be quite robust within a wide range of operating regimes for a generic combined cycle system. As such, a second law based approach to off-design performance estimation is a highly viable tool for plant engineers and operators in cases where calculation speed with a small sacrifice in fidelity is of prime importance.

Daesan Combined Cycle Power Plant: Successful Operating Experience on Low Sulphur Waxy Residual Fuel Oil

2001 ◽  
Author(s):  
Koen-Woo Lee ◽  
Hwan-Doo Kim ◽  
Sung-Il Wi ◽  
Jean-Pierre Stalder
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Capital Expenditure ◽  
Operating Experience ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Heat Recovery Boiler ◽  
Particulate Emissions ◽  
Combined Cycle Power Plant ◽  
Residual Fuel Oil

This paper presents and discusses the successful operating experience and the issues related to burning low sulphur waxy residual (LSWR) fuel oil at the 507 MW IPP Daesan Combined Cycle Power Plant. The power plant was built and is operated by Hyundai Heavy Industries (HHI). It comprises four Siemens-Westinghouse 501D5 engines, each with a heat recovery boiler including supplementary firing and one steam turbine. This plant, commissioned in 1997, is designed to burn LSWR fuel oil. LSWR fuel oil was selected because of the lower fuel cost as compared to LNG and other liquid fuels available in Korea. By adding a combustion improver to the LSWR fuel oil it is possible for HHI to comply with the tight Korean environmental regulations, despite the tendency for heavy smoke and particulate emissions when burning this type of fuel oil. The successful operating experience, availability, reliability and performance achieved in Daesan, as well as the commercial viability (which by far offsets the additional capital expenditure and the additional related O&M costs) demonstrate that LSWR fuel oil firing in heavy duty gas turbines is rewarding. This is especially important in view of the growing disposal problems of residuals at refineries around the world.

Exergoeconomic Analysis of a Combined Cycle of Three Levels of Pressure

2016 ◽  
Author(s):  
Edgar Vicente Torres González ◽  
Raúl Lugo-Leyte ◽  
Martín Salazar-Pereyra ◽  
Miguel Toledo Velázquez ◽  
Helen Denise Lugo-Méndez ◽  
...  
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Systematic Approach ◽  
Combined Cycle ◽  
Exergetic Efficiency ◽  
Steam Generators ◽  
Combined Cycle Power Plant ◽  
Exergoeconomic Analysis ◽  
The Cost

This paper presents an exergoeconomic analysis of the combined cycle power plant Tuxpan II located in Mexico. The plant is composed of two identical modules conformed by two gas turbines generating the required work and releasing the hot exhaust gases in two heat recovery steam generators. These components generate steam at three different pressure levels, used to produce additional work in one steam turbine. The productive structure of the considered system is used to visualize the cost formation process as well as the productive interaction between their components. The exergoeconomic analysis is pursued by 1) carrying out a systematic approach, based on the Fuel-Product methodology, in each component of the system; and 2) generating a set of equations, which allows compute the exergetic and exergoeconomic costs of each flow. The thermal and exergetic efficiency of the two gas turbines delivering 278.4 MW are 35.16% and 41.90% respectively. The computed thermal efficiency of the steam cycle providing 80.96 MW is 43.79%. The combined cycle power plant generates 359.36 MW with a thermal and exergetic efficiency of 47.27% and 54.10% respectively.

Effect of Inlet Air Cooling by Ice Storage on Unit Sizing of a Gas Turbine Cogeneration Plant

2004 ◽  
Vol 126 (2) ◽  
pp. 351-357 ◽  
Author(s):  
Ryohei Yokoyama ◽  
Koichi Ito
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Maximum Power ◽  
Mixed Integer ◽  
Ice Storage ◽  
Air Cooling ◽  
Cogeneration Plant ◽  
Maximum Heat ◽  
Maximum Power Output

In the commercial sector, heat and power demands peak in the summer daytime because of high space cooling demands, and cogeneration plants are required to produce maximum heat and power to meet their demands. However, gas turbine cogeneration plants have the disadvantage of decreases in maximum power output in the summer daytime, which reduces the availability of gas turbines. One of the ways to avoid the aforementioned disadvantage is to cool inlet air and augment maximum power output. In addition, one of the ways for inlet air cooling is to make ice by driving electric compression refrigerators using off-peak power generated during the nighttime, store it in ice banks, and use its heat for inlet air cooling during the on-peak period. The objective of this paper is to investigate the effect of inlet air cooling by ice storage on the unit sizing and cost of a gas turbine cogeneration plant. An optimal unit sizing method based on the mixed-integer linear programming is used to rationally determine equipment capacities and operational strategies of the plant. A numerical study is conducted, in which the gas turbine cogeneration plants with and without inlet air cooled by ice storage are compared with each other, and the effect of inlet air cooling on the equipment capacities as well as the annual total cost and its items is clarified.

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